After LW has been open for at least 30 mins, Do this test: Bug Report instructions & sample image Is it True/False?

Can you tell us your Connection type?
And Modem & Router brand name & model numbers?

Did you update your Java?: Java 1.5 (take the JRE)

Check your firewall settings within LW: Tools>Options>Advanced>Firewalls & select Use UPnP & press Apply.